1. Field of the Invention
The present invention relates to a chain saw having a plunger type oil pump for supplying lubrication oil to a saw chain and an oil flow path through which oil discharged from the oil pump is supplied to a chain guide groove in a guide bar of the saw chain.
2. Description of the Prior Art
In a prior art chain saw, a cylinder of an oil pump is formed integrally with a body of the oil pump. Due to such a structure, a hole is formed in the pump body from the outside and is precisely worked into an exact cylinder. The cylinder is closed at its outer end by a cover member. Also, the oil flow path is bored in the chain saw body. The oil flow hole is at one end in communication and alignment with an outlet path of the oil pump and is connected at the other end to an oil supply port of the guide bar (through a metal pipe or the like).
Such a structure requires precision working or machining for both the pump body and the chain saw body. This needs a large amount of work and cost for manufacture of the chain saw. Also, elaborate work is needed to avoid possible leakage of oil from the outlet passage of the oil pump, the contacting surface between the oil supply port of the guide bar and the hole of the oil pump body and the like. Therefore, the arrangement and mounting of these components are unduly limited.